moléculas orgánicas proteina qui403 usc
TRANSCRIPT
Carbon Atoms
• form four covalent bonds– single, double, or triple– straight or branched chains– rings
• bond with many different elements
Fig. 3-1, p. 46
C
H
H
H H C
H
H
H OH C
O
H OHC
O
H H
C
H
H
H C
H
H
H C
H
H
H C
H
H
OH C
H
H
H C
O
H C
O
OHC
H
H
H
C
H
H
HC
H
H
H C
O
C
H
H
HC
H
H
H C
H
HC
H
H
OHC
H
H
H C
H
H
C
H
O
HC
H
H
H C
H
C
H
O
OHC
H
H
H C
H
Animation: Functional Group
Table 3-1a, p. 49
Table 3-1b, p. 49
Polymers and Macromolecules
• Polymers – long chains of monomers – linked through condensation reactions
• Macromolecules – large polymers– polysaccharides, proteins, and DNA– broken down by hydrolysis reactions
Condensation and Hydrolysis
Monosaccharides
Fig. 3-6, p. 51
Dihydroxyacetone (C3H6O3)(a ketone)
(a) Triose sugars (3-carbon sugars)
Glyceraldehyde (C3H6O3)(an aldehyde)
Fig. 3-6, p. 51
Disaccharides
Polysaccharides
• Starch Glycogen
• Starch • Glycogen
Cellulose
**chitosan
Chitin
• Triglycerides = three fatty acids attached to one molecule of glycerol
Triglyceride Formation
Figure 2.15
Lipids
Triacylglycerol
Fatty acids
Figure 2.13
Fig. 3-13, p. 58
Fatty acidsCholine
PhosphategroupGlycerol
Hydrophilichead
Hydrophobictail
Water
Steroids
• Carbon atoms arranged in 4 rings – cholesterol, bile salts, some hormones
Figure 2.16 Steroids
Figure 2.16
Estructura y función de las proteínas
DNA MoleculeNucleic Acid
Nucleic Acid
• RNA
Nucleotides
• ATP (adenosine triphosphate)– essential in energy metabolism
• NAD+ – electron acceptor in biological oxidation and
reduction reactions
Fig. 4-6, p. 81
Plasmamembrane
0.5 μm
Pili
Storage granule
FlagellumRibosome
Cell wall
CapsuleNucleararea
DNA
• The cell membrane is a phospholipid bilayer with proteins, lipids and carbohydrates.
Figure 3.3
Sistema de Endomembranas
Peroxisomas
Figure 3.11
Lisosomas
Fig. 4-19, p. 95
Cristae
0.25 μm
Outermitochondrialmembrane
Innermitochondrialmembrane
Matrix
Mitocondrias
Figure 2.5
H2O
Figure 2.6
Na+ Cl-
Fig. 3-1, p. 46
Moléculas no polares son insolubles en agua o hidrofóbicas
Solubilidad de hexanol = 0.0058 mol/100g H2OSolubilidad de glucosa = 0.5 mol/100g H2O hexanol
Figure 2.8
Moléculas anfipáticas
Fig. 3-13, p. 58
Fatty acidsCholine
PhosphategroupGlycerol
Hydrophilichead
Hydrophobictail
Water
Ionización del Agua
Kw = [1 X 10-7 M ] [1 X 10-7 M ] = 1 X 10-14 M2
[ H+ ] =1 X 10-7 M
Kw = [ H+ ] [OH- ] = 1 X 10-14 M2 constante de producto iónico del agua
[ OH- ] = 1 X 10-7 M
pH = - log [H+] = 7
pOH = - log [OH-] = 7
H2O H+ + OH-
ácido base
Kw= keq [H2O]
Figure 2.9
pH = - log [H+] [H+] = 1 x 10-pH
Metros de pH
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• Acids release hydrogen ions into solution• Bases remove hydrogen ions from solution
• Strong acids and strong bases ionize completely
Acids and Bases
HCL H+ + CL
NaOH Na+ + OH
OH + H+ H2O
NaOH + HCl NaCl + H2O
ácido
base
HCl -- pH ácido
NaOH -- pOH base
NaOH + HCl NaCl + H2O
pH = - log [H+]
[H+] = 1 x10-pH :. [H+] = 10-pH
1. Busque el pH para los siguientes: a) HCl 0.0001M b) HCl 0.01M c) NaOH 0.0001M d) HCl 0.0013M e) NaOH 0.00008M 2. Busque la concentración del [H+] para los siguientes: a) pH = 3 b) pH = 9 c) pH = 5 d) pOH = 9 e) pOH = 4
CH3COOH H+ + CH3CO¯
ácidos débiles
Ka = [H+] [A-] [HA]
HA H++ A-
Ka = [H+] [CH3CO¯] [CH3COOH]
CO
OHCH
HH C
O
O¯CH
HH + H+
* pKa = 4.75448
CH3COOH H+ + CH3CO¯ácidos débiles
Ka = [H+] [A-] [HA]
log Ka = log [H+] + log [A-] [HA]
-log [H+] = - log Ka + log [A-] [HA]
pH = pKa + log [A-] [HA]
Henderson-Hasselbalck
Si [HA] = [A- ] :.pH = pKa + 0
HA H++ A-
Acetic acid pK=4.8 Prepare a Buffer pH=5.8
pH = pKa + log [A-] [HA]
5.8 = 4.8 + log [Acetate] [Acetic Acid]
5.8 - 4.8 = log [Acetate] [Acetic Acid]
1 = log [Acetate] [Acetic Acid]
101 = [Acetate] [Acetic Acid]
10 [Acetic Acid] = 1 [Acetate]
CH3COOH H+ + CH3CO
Acidos Débiles
PBS(PhosphateBufferedSaline) for pH 7.4
AmortiguadoresH2O + CO2 H2CO3 HCO3
+ H+
H2O + CO2 H2CO3 HCO3 + H+
NaCL Na+ + Cl
HCL NaHCO3
Ácido clorhídrico Bicarbonato de Sodio
Estructura y función de las proteínas
¿Funciones?
1. Many proteins function as enzymes, the biochemical catalysts.
2. Some proteins bind other molecules for storage and transport.
3. Several types of proteins serve as pores and channels in membranes
4. Some proteins provide support and shape to cells and tissues.
5. Assemblies of proteins can do mechanical work
6. Some are involved in translation whereas others play a role in regulating gene expression by binding to nucleic acids.
7. Some proteins are hormones other proteins serve as receptors for hormones.
9. Some proteins are antibodies to defend against bacterial and viral infections.
N- terminal C-Terminal
Glutamato Histidina
Tyrosina Tyrosina
Serotonin(Tryptophan)
GABA(Glutamate)Glutamate
Glycine Dopamine Norepinephrine Epinephrine
Neurotransmitters
Histamine
Dipolar Ions
Amino acid pKa1 pKa2 pKa3 pIGlycine 2.34 9.60 --- 5.97Alanine 2.34 9.69 --- 6.00Valine 2.32 9.62 --- 5.96Leucine 2.36 9.60 --- 5.98Isoleucine 2.36 9.60 --- 6.02Methionine 2.28 9.21 --- 5.74Proline 1.99 10.60 --- 6.30Phenylalanine 1.83 9.13 --- 5.48Tryptophan 2.83 9.39 --- 5.89Asparagine 2.02 8.80 --- 5.41Glutamine 2.17 9.13 --- 5.65Serine 2.21 9.15 --- 5.68Threonine 2.09 9.10 --- 5.60Tyrosine 2.20 9.11 --- 5.66Cysteine 1.96 8.18 --- 5.07Aspartic acid 1.88 9.60 3.65 2.77Glutamic acid 2.19 9.67 4.25 3.22Lysine 2.18 8.95 10.53 9.74
Arginine 2.17 9.04 12.48 10.76Histidine 1.82 9.17 6.00 7.59
Table of pKa and pI values
•The pKa values and the isoelectronic point, pI, are given below for the 20 α-amino acids. •pKa1= α-carboxyl group, pKa2 = α-ammonium ion, and pKa3 = side chain group.
Primary Structure• Linear sequence of amino acids in
polypeptide chain
N- terminal C-Terminal
Secondary Structure
Amino ácidos polares hacia el agua y no polares hacia adentro
Tertiary Structure
Motifs
Domains Pyruvate kinase from cat
Domains
Tertiary structure of polypeptide
Estructura terciaria y pH
Lactate dehydrogenase Malate dehydrogenase
Citocromo Cb- tunac- riced- yeaste- bacterial
Aplysia myoglobin Tuna myoglobin Whale myoglobin Human myoglobin
Alzheimer's disease has been identified as a protein misfolding disease, or proteopathy, due to the accumulation of abnormally folded Amyloid-beta proteins in the brains of AD patients.[1] Amyloid-beta, also written Aβ, is a short peptide that is a proteolytic byproduct of the transmembrane protein amyloid precursor protein (APP), whose function is unclear but thought to be involved in neuronal development. The presenilins are components of a proteolytic complex involved in APP processing and degradation.[3] Although amyloid beta monomers are harmless, they undergo a dramatic conformational change at sufficiently high concentration to form a beta sheet-rich tertiary structure that aggregates to form amyloid fibrils[6] that deposit outside neurons in dense formations known as senile plaques or neuritic plaques.
AD is also considered a tauopathy due to abnormal aggregation of the tau protein, a microtubule-associated protein expressed in neurons that normally acts to stabilize microtubules in the cell cytoskeleton. Like most microtubule-associated proteins, tau is normally regulated by phosphorylation; however, in AD patients, hyperphosphorylated tau accumulates as paired helical filaments[7] that in turn aggregate into masses inside nerve cell bodies known as neurofibrillary tangles and as dystrophic neurites associated with amyloid plaques.
Enzyme-Substrate Complex• Substrate binds to enzyme’s active site
– forming enzyme–substrate complex – changes shapes of enzyme and substrate– induced fit helps break and form bonds
Quaternary Structure
Reverse transcriptase(RNA-dependent DNA polymerase)
Figure 19.3
Myoglobin b subunit ofhemoglobin
Color code: -globin (blue), -globin (purple), myoglobin (green).
Chemical structure of the Fe(II)-protoporphyrin IX heme group inmyoglobin and hemoglobin.
Figure 23.21
Figure 23.22a, b
BPGAllosteric modulator
Antibody Diversity
Figure 10–1
Figure 10–3
Figure 10–13
A Thin Filament
Figure 10–7a
Troponin and Tropomyosin
Figure 10–7b
A Thick Filament
Figure 10–7c
The Mysosin Molecule
Figure 10–7d
Sliding Filaments
Figure 10–8
Skeletal Muscle Innervation
Figure 10–10a, b (Navigator)
Figure 10–9 (Navigator)
Figure 10–11
Regulación de la contracción por Ca++
Copyright © 2009 Pearson Education, Inc., publishing as Pearson Benjamin Cummings
The Contraction Cycle
Figure 10–12 The Contraction Cycle.
Copyright © 2009 Pearson Education, Inc., publishing as Pearson Benjamin Cummings
The Contraction Cycle
[INSERT FIG. 10.12, step 1]
Figure 10–12 The Contraction Cycle.
Copyright © 2009 Pearson Education, Inc., publishing as Pearson Benjamin Cummings
The Contraction Cycle
Figure 10–12 The Contraction Cycle.
Copyright © 2009 Pearson Education, Inc., publishing as Pearson Benjamin Cummings
The Contraction Cycle
Figure 10–12 The Contraction Cycle.
Copyright © 2009 Pearson Education, Inc., publishing as Pearson Benjamin Cummings
The Contraction Cycle
Figure 10–12 The Contraction Cycle.
Copyright © 2009 Pearson Education, Inc., publishing as Pearson Benjamin Cummings
The Contraction Cycle
Figure 10–12 The Contraction Cycle.